The list of ship decommissionings in 2021 includes a chronological list of ships decommissioned in 2021.
| Operator | Ship | Class and type | Fate | Other notes | |
|---|---|---|---|---|---|
| 9 March | Louisville [1] | Los Angeles-class submarine | |||
| 27 March | Fort McHenry [2] | Whidbey Island-class dock landing ship | |||
| 15 April | Bonhomme Richard [3] | Wasp-class amphibious assault ship | |||
| 21 May | Bremerton [2] | Los Angeles-class submarine | |||
| 1 July | Var [4] | Durance-class tanker | |||
| 29 July | Independence [5] | Independence-class littoral combat ship | |||
| 4 August | Blyth [6] | Sandown-class minehunter | |||
| 4 August | Ramsey [7] | Sandown-class minehunter | |||
| 29 September | Freedom [8] | Freedom-class littoral combat ship | |||
| 16 November | Jacksonville [9] | Los Angeles-class submarine |